The present invention relates to a golf club head, more particularly to a structure which can lower and deepen the center of gravity, while mitigating the shock that the user's hands get at the time of a miss shot.
It is of course desirable but difficult for amateur golfers to hit a golf ball at the sweet spot of a golf club head. If a golf ball is hit off the sweet spot, the golfer's hands get experience a relatively large shock, and the hit feel is not good. This is especially remarkable in an iron-type club head provided with a backside wall for the purpose of deepening the center of gravity.
The present inventor therefore, made a study on the behavior of each portion of such a head at impact and found the major cause of the relatively large shock. Due to impact, the backside wall of the head is vibrated like a tuning fork as shown in FIG. 8, causing vibration having a duration that is relatively long and an amplitude of the vibration that becomes a maximum at the free end of the backside wall. If the toe-side and heel-side ends of the backside wall are fixed, a vibration mode as shown in FIG. 9 is liable to occur. If they are free ends, the entirety is liable to vibrate as shown in FIG. 10 with the same amplitude along the entire length. Such a vibration travels through the shaft to the user's hands as a bad vibratory shock.